<?php

    /*
     * Abraham Williams (abraham@abrah.am) http://abrah.am
     *
     * The first PHP Library to support OAuth for Twitter's REST API.
     */

    /* Load OAuth lib. You can find it at http://oauth.net */
    require_once('OAuth.php');

    /**
     * Twitter OAuth class
     */
    class TwitterOAuth
    {
        /* Contains the last HTTP status code returned. */

        public $http_code;
        /* Contains the last API call. */
        public $url;
        /* Set up the API root URL. */
        public $host = "https://api.twitter.com/1.1/";
        /* Set timeout default. */
        public $timeout = 30;
        /* Set connect timeout. */
        public $connecttimeout = 30;
        /* Verify SSL Cert. */
        public $ssl_verifypeer = FALSE;
        /* Respons format. */
        public $format = 'json';
        /* Decode returned json data. */
        public $decode_json = TRUE;
        /* Contains the last HTTP headers returned. */
        public $http_info;
        /* Set the useragnet. */
        public $useragent = 'TwitterOAuth v0.2.0-beta2';

        /* Immediately retry the API call if the response was not successful. */
        //public $retry = TRUE;

        /**
         * Set API URLS
         */
        function accessTokenURL()
        {
            return 'https://api.twitter.com/oauth/access_token';
        }

        function authenticateURL()
        {
            return 'https://api.twitter.com/oauth/authenticate';
        }

        function authorizeURL()
        {
            return 'https://api.twitter.com/oauth/authorize';
        }

        function requestTokenURL()
        {
            return 'https://api.twitter.com/oauth/request_token';
        }

        /**
         * Debug helpers
         */
        function lastStatusCode()
        {
            return $this->http_status;
        }

        function lastAPICall()
        {
            return $this->last_api_call;
        }

        /**
         * construct TwitterOAuth object
         */
        function __construct($consumer_key, $consumer_secret, $oauth_token = NULL, $oauth_token_secret = NULL)
        {
            $this->sha1_method = new OAuthSignatureMethod_HMAC_SHA1();
            $this->consumer = new OAuthConsumer($consumer_key, $consumer_secret);
            if (!empty($oauth_token) && !empty($oauth_token_secret))
            {
                $this->token = new OAuthConsumer($oauth_token, $oauth_token_secret);
            }
            else
            {
                $this->token = NULL;
            }
        }

        /**
         * Get a request_token from Twitter
         *
         * @returns a key/value array containing oauth_token and oauth_token_secret
         */
        function getRequestToken($oauth_callback)
        {
            $parameters = array();
            $parameters['oauth_callback'] = $oauth_callback;
            $request = $this->oAuthRequest($this->requestTokenURL(), 'GET', $parameters);
            $token = OAuthUtil::parse_parameters($request);
            $this->token = new OAuthConsumer($token['oauth_token'], $token['oauth_token_secret']);
            return $token;
        }

        /**
         * Get the authorize URL
         *
         * @returns a string
         */
        function getAuthorizeURL($token, $sign_in_with_twitter = TRUE)
        {
            if (is_array($token))
            {
                $token = $token['oauth_token'];
            }
            if (empty($sign_in_with_twitter))
            {
                return $this->authorizeURL() . "?oauth_token={$token}";
            }
            else
            {
                return $this->authenticateURL() . "?oauth_token={$token}";
            }
        }

        /**
         * Exchange request token and secret for an access token and
         * secret, to sign API calls.
         *
         * @returns array("oauth_token" => "the-access-token",
         *                "oauth_token_secret" => "the-access-secret",
         *                "user_id" => "9436992",
         *                "screen_name" => "abraham")
         */
        function getAccessToken($oauth_verifier)
        {
            $parameters = array();
            $parameters['oauth_verifier'] = $oauth_verifier;
            $request = $this->oAuthRequest($this->accessTokenURL(), 'GET', $parameters);
            $token = OAuthUtil::parse_parameters($request);
            $this->token = new OAuthConsumer($token['oauth_token'], $token['oauth_token_secret']);
            return $token;
        }

        /**
         * One time exchange of username and password for access token and secret.
         *
         * @returns array("oauth_token" => "the-access-token",
         *                "oauth_token_secret" => "the-access-secret",
         *                "user_id" => "9436992",
         *                "screen_name" => "abraham",
         *                "x_auth_expires" => "0")
         */
        function getXAuthToken($username, $password)
        {
            $parameters = array();
            $parameters['x_auth_username'] = $username;
            $parameters['x_auth_password'] = $password;
            $parameters['x_auth_mode'] = 'client_auth';
            $request = $this->oAuthRequest($this->accessTokenURL(), 'POST', $parameters);
            $token = OAuthUtil::parse_parameters($request);
            $this->token = new OAuthConsumer($token['oauth_token'], $token['oauth_token_secret']);
            return $token;
        }

        /**
         * GET wrapper for oAuthRequest.
         */
        function get($url, $parameters = array())
        {
            $response = $this->oAuthRequest($url, 'GET', $parameters);
            if ($this->format === 'json' && $this->decode_json)
            {
                return json_decode($response);
            }
            return $response;
        }

        /**
         * POST wrapper for oAuthRequest.
         */
        function post($url, $parameters = array())
        {
            $response = $this->oAuthRequest($url, 'POST', $parameters);
            if ($this->format === 'json' && $this->decode_json)
            {
                return json_decode($response);
            }
            return $response;
        }

        /**
         * DELETE wrapper for oAuthReqeust.
         */
        function delete($url, $parameters = array())
        {
            $response = $this->oAuthRequest($url, 'DELETE', $parameters);
            if ($this->format === 'json' && $this->decode_json)
            {
                return json_decode($response);
            }
            return $response;
        }

        /**
         * Format and sign an OAuth / API request
         */
        function oAuthRequest($url, $method, $parameters)
        {
            if (strrpos($url, 'https://') !== 0 && strrpos($url, 'http://') !== 0)
            {
                $url = "{$this->host}{$url}.{$this->format}";
            }
            $request = OAuthRequest::from_consumer_and_token($this->consumer, $this->token, $method, $url, $parameters);
            $request->sign_request($this->sha1_method, $this->consumer, $this->token);
            switch ($method)
            {
                case 'GET':
                    return $this->http($request->to_url(), 'GET');
                default:
                    return $this->http($request->get_normalized_http_url(), $method, $request->to_postdata());
            }
        }

        /**
         * Make an HTTP request
         *
         * @return API results
         */
        function http($url, $method, $postfields = NULL)
        {
            $this->http_info = array();
            $ci = curl_init();
            /* Curl settings */
            curl_setopt($ci, CURLOPT_USERAGENT, $this->useragent);
            curl_setopt($ci, CURLOPT_CONNECTTIMEOUT, $this->connecttimeout);
            curl_setopt($ci, CURLOPT_TIMEOUT, $this->timeout);
            curl_setopt($ci, CURLOPT_RETURNTRANSFER, TRUE);
            curl_setopt($ci, CURLOPT_HTTPHEADER, array('Expect:'));
            curl_setopt($ci, CURLOPT_SSL_VERIFYPEER, $this->ssl_verifypeer);
            curl_setopt($ci, CURLOPT_HEADERFUNCTION, array($this, 'getHeader'));
            curl_setopt($ci, CURLOPT_HEADER, FALSE);

            switch ($method)
            {
                case 'POST':
                    curl_setopt($ci, CURLOPT_POST, TRUE);
                    if (!empty($postfields))
                    {
                        curl_setopt($ci, CURLOPT_POSTFIELDS, $postfields);
                    }
                    break;
                case 'DELETE':
                    curl_setopt($ci, CURLOPT_CUSTOMREQUEST, 'DELETE');
                    if (!empty($postfields))
                    {
                        $url = "{$url}?{$postfields}";
                    }
            }

            curl_setopt($ci, CURLOPT_URL, $url);
            $response = curl_exec($ci);
            $this->http_code = curl_getinfo($ci, CURLINFO_HTTP_CODE);
            $this->http_info = array_merge($this->http_info, curl_getinfo($ci));
            $this->url = $url;
            curl_close($ci);
            return $response;
        }

        /**
         * Get the header info to store.
         */
        function getHeader($ch, $header)
        {
            $i = strpos($header, ':');
            if (!empty($i))
            {
                $key = str_replace('-', '_', strtolower(substr($header, 0, $i)));
                $value = trim(substr($header, $i + 2));
                $this->http_header[$key] = $value;
            }
            return strlen($header);
        }

    }

    